These do it yourself Metal Earth model kits begin as 4 inch steel sheets, and when completed create a fabulous 3D miniature model! Easy to follow printed instructions are included in every package. Discovery was the third NASA orbiter to be built. It first launched August 30, 1984 and remained in service for more than 27 years. Among its many accomplishments was the work done on the International Space Station and carrying the Hubble Space Telescope into orbit. This detailed moderate level model of Discovery contains 2 sheets and measures about 4.5"L x 2.8"W x 2.3"H when completed.